Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cereb...Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.展开更多
目的:探讨参附注射液(SFI)对缺氧缺血性脑损伤(HIBD)新生大鼠eIF2α(p)、ATF4的影响。方法:参照Rice法制备新生大鼠HIBD模型,将7日龄新生SD大鼠随机分为假手术组(S)、生理盐水对照组(C)和参附治疗组(SF),每组按术后观察时间点不同进一...目的:探讨参附注射液(SFI)对缺氧缺血性脑损伤(HIBD)新生大鼠eIF2α(p)、ATF4的影响。方法:参照Rice法制备新生大鼠HIBD模型,将7日龄新生SD大鼠随机分为假手术组(S)、生理盐水对照组(C)和参附治疗组(SF),每组按术后观察时间点不同进一步分为HI后6、12、24和72 h 4个亚组。用免疫组织化学方法检测病变侧大脑皮质eIF2α(p)、ATF4水平。结果:C组和SF组eIF2α(p)、ATF4表达水平均较S组升高,差异有统计学意义(P<0.01)。eIF2α(p)、ATF4在HI后12 h达到高峰。HI后6、12、24、72 h SF组eIF2α(p)、ATF4表达水平均低于相应时间点的C组,差异有统计学意义(P<0.01)。结论:HIBD后大鼠病变侧大脑皮质eIF2α(p)、ATF4水平明显升高,SFI下调HIBD新生大鼠eIF2α(p)、ATF4的水平,SFI对新生大鼠HIBD有保护作用。展开更多
We previously found that oxygen-glucose-serum deprivation/restoration（OGSD/R） induces apoptosis of spinal cord astrocytes, possibly via caspase-12 and the integrated stress response, which involves protein kinase R-...We previously found that oxygen-glucose-serum deprivation/restoration（OGSD/R） induces apoptosis of spinal cord astrocytes, possibly via caspase-12 and the integrated stress response, which involves protein kinase R-like endoplasmic reticulum kinase（PERK）, eukaryotic initiation factor 2-alpha（eIF2α） and activating transcription factor 4（ATF4）. We hypothesized that edaravone, a low molecular weight, lipophilic free radical scavenger, would reduce OGSD/R-induced apoptosis of spinal cord astrocytes. To test this, we established primary cultures of rat astrocytes, and exposed them to 8 hours/6 hours of OGSD/R with or without edaravone（0.1, 1, 10, 100 μM） treatment. We found that 100 μM of edaravone significantly suppressed astrocyte apoptosis and inhibited the release of reactive oxygen species. It also inhibited the activation of caspase-12 and caspase-3, and reduced the expression of homologous CCAAT/enhancer binding protein, phosphorylated（p）-PERK, p-eIF2α, and ATF4. These results point to a new use of an established drug in the prevention of OGSD/R-mediated spinal cord astrocyte apoptosis via the integrated stress response.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82260245(to YX),81660207(to YX),81960253(to YL),82160268(to YL),U1812403(to ZG)Science and Technology Projects of Guizhou Province,Nos.[2019]1440(to YX),[2020]1Z067(to WH)+1 种基金Cultivation Foundation of Guizhou Medical University,No.[20NSP069](to YX)Excellent Young Talents Plan of Guizhou Medical University,No.(2022)101(to WH)。
文摘Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.
文摘目的:探讨参附注射液(SFI)对缺氧缺血性脑损伤(HIBD)新生大鼠eIF2α(p)、ATF4的影响。方法:参照Rice法制备新生大鼠HIBD模型,将7日龄新生SD大鼠随机分为假手术组(S)、生理盐水对照组(C)和参附治疗组(SF),每组按术后观察时间点不同进一步分为HI后6、12、24和72 h 4个亚组。用免疫组织化学方法检测病变侧大脑皮质eIF2α(p)、ATF4水平。结果:C组和SF组eIF2α(p)、ATF4表达水平均较S组升高,差异有统计学意义(P<0.01)。eIF2α(p)、ATF4在HI后12 h达到高峰。HI后6、12、24、72 h SF组eIF2α(p)、ATF4表达水平均低于相应时间点的C组,差异有统计学意义(P<0.01)。结论:HIBD后大鼠病变侧大脑皮质eIF2α(p)、ATF4水平明显升高,SFI下调HIBD新生大鼠eIF2α(p)、ATF4的水平,SFI对新生大鼠HIBD有保护作用。
基金supported by a grant from the Science&Technology Bureau of Changzhou City of China,No.CJ20130029
文摘We previously found that oxygen-glucose-serum deprivation/restoration（OGSD/R） induces apoptosis of spinal cord astrocytes, possibly via caspase-12 and the integrated stress response, which involves protein kinase R-like endoplasmic reticulum kinase（PERK）, eukaryotic initiation factor 2-alpha（eIF2α） and activating transcription factor 4（ATF4）. We hypothesized that edaravone, a low molecular weight, lipophilic free radical scavenger, would reduce OGSD/R-induced apoptosis of spinal cord astrocytes. To test this, we established primary cultures of rat astrocytes, and exposed them to 8 hours/6 hours of OGSD/R with or without edaravone（0.1, 1, 10, 100 μM） treatment. We found that 100 μM of edaravone significantly suppressed astrocyte apoptosis and inhibited the release of reactive oxygen species. It also inhibited the activation of caspase-12 and caspase-3, and reduced the expression of homologous CCAAT/enhancer binding protein, phosphorylated（p）-PERK, p-eIF2α, and ATF4. These results point to a new use of an established drug in the prevention of OGSD/R-mediated spinal cord astrocyte apoptosis via the integrated stress response.
